This invention relates to improvements in a process for producing works of sculpture on the basis of stereoscopic photography.
One of the stereophotographic processes known in the art for manufacturing statuary is as follows. Some projectors and some cameras are alternately arranged in a circle around an object to face it concentrically. Each of the projectors is fitted with a screen having a number of parallel vertical lines or stripes as indicated in FIG. 2, and the projectors throw the striped patterns of the screens on the object at the center. The object in this state is photographed simultaneously with the cameras. (For the purposes of the invention the procedure up to this point is called a "photographing step".) Next, the object is replaced by a mass of material to be modeled to form a work of sculpture, that is, an original model on the basis of stereophotography. At the same time, the cameras are removed and the same number of additional projectors are installed at the corresponding points. The additional projectors are loaded with the positives of the pictures taken by the cameras in the same positions, whereas the original projectors remain fitted with the screens. Either the pictures alone or the pictures and the screens are projected on the material surface. Each picture represents the pattern of parallel stripes of the screen projected from the same point against the object and photographed, in the preceding photographing step, as deformed according to the surface configurations of the object. For example, if the object is a spherical body and screens of the pattern as shown in FIG. 2 are projected on it from both sides of a camera, the parallel stripes of the two screens will be photographed as deformed to curves as indicated in FIG. 4. Now if either two such pictures or one such screen and one such picture are projected on a mass of material by the same projectors, the material surface will look striped in black. The operator or sculptor then models the material, building up or cutting it away, so that the black stripes projected separately will meet and coincide on the material surface, when the material takes the form of an original model analogous to the object. This is a conventional process for producing statuary on the basis of stereoscopic photography.
The process renders it necessary for the sculptor to check every stripe on the material being modeled and make certain that the stripe patterns on the finished model are in perfect coincidence, even in the edge portions. This adds greatly to the production time. In addition, because frequent overlook of unmatched stripes can result from the complexity and indistinctness of the overlapping patterns, the original model thus obtained stereophotographically is sometimes not an exact replica of the object.